Kata Kunci PHP-tutorial php-php.cn

Kata kunci ialah perkataan yang mempunyai beberapa makna. Dalam penggunaan biasa bahasa PHP, perkataan ini tidak boleh digunakan sebagai pemalar, nama pembolehubah, nama kaedah, nama kelas, dll. Kata kunci ini apabila digunakan secara automatik difahami oleh PHP. Kata kunci PHP ini, apabila digunakan dengan nama pembolehubah, boleh dikelirukan dengan kata kunci sebenar. Oleh itu, kata kunci ini tidak boleh digunakan sebagai nama pembolehubah.

IKLAN Kursus Popular dalam kategori ini PEMBANGUN PHP - Pengkhususan | 8 Siri Kursus | 3 Ujian Olok-olok

Mulakan Kursus Pembangunan Perisian Percuma Anda

Pembangunan web, bahasa pengaturcaraan, ujian perisian & lain-lain

Senarai semua kata kunci PHP

Berikut ialah senarai:

Kata Kunci PHP

Kata kunci: abstrak

Kod:

<?php
//example to demonstrate abstract keyword
abstract class Program {
abstract protected function MethodOne();
public function display() {
echo '<br>'.$this->MethodOne();
}
}
class ProgramOne extends Program {
protected function MethodOne() {
echo '<br>'.'In MethodOne';
}
}
$objOne = new ProgramOne;
$objOne->display();
?>,

Salin selepas log masuk

Output:

Kata Kunci PHP

Kata kunci: dan

Kod :

<?php
//example to demonstrate and keyword
$a = 10;
$b = 11;
if($a ==10  and  $b == 11) {
echo 'Result :  True';
}
else
{
echo 'Result : False';
}
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Kata kunci: array()

Kod:

<?php
//example to demonstrate array keyword
$directions  = array("e" => "east", "w" => "west", "n" => "north", "s" => "south");
print_r($directions);
?>

Salin selepas log masuk

Output:

Kata kunci: sebagai

Kod:

<?php
//example to demonstrate array keyword
$directions  = array("e" => "east", "w" => "west", "n" => "north", "s" => "south");
foreach($directions as $key=>$value) {
echo '<br>'. $key. '=>'.$value;
}
?>

Salin selepas log masuk

Output:

Kata kunci: putus

Kod :

<?php
//use of break keyword without optional argument
$arr = array("water", "sky", "try", "sand");
foreach($arr as $key=>$value) {
if($value  == 'try') {
break ;          // can use break 1 also
}
echo '<br>'.$value;
}
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Kata kunci: kes

Kod:

<?php
//example to demonstrate case keyword
$i = 1;
while($i<5) {
switch($i) {
case 1:
echo "<br>"."One";
break;
case 2:
echo "<br>"."Two";
break;
case 3:
echo "<br>"."Three";
break;
default:
echo "<br>"."Default";
}
$i++;
}
?>

Salin selepas log masuk

Output:

Kata kunci: tangkap

Kod:

<?php
//example to demonstrate catch keyword
function Operation()
{
try {
$num1 = 10;
$num2 = 0;
if($num1 / $num2) {
throw new Exception('Divide By Zero');
}
} catch (Exception $e) {
die($e->getMessage());
}
}
Operation();
?>

Salin selepas log masuk

Output:

Kata kunci: kelas

Kod:

<?php
//example to demonstrate class keyword
class ClassOne{
var $str = 'Hello World';
public function displayMethod() {
echo $this->str;
}
}
$obj = new ClassOne;
$obj->displayMethod();
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Kata kunci: const

kata kunci const digunakan untuk mentakrifkan nama dengan nilai menggunakan operator tugasan seperti di bawah

UMUR konst= 29;

Tiada tanda $ pada permulaan nama tetap seperti pembolehubah biasa.

Kata kunci: lalai

Kod:

<?php
// example to demonstrate default keyword
$fruits = 'Cherries';
switch ($fruits) {
case 'Apple':
echo "Apple";
break;
case 'Banana':
echo "Banana";
break;
case 'Papaya':
echo "Papaya";
break;
default:
echo "Fruit is not Apple, Banana or Papaya ";
break;
}
?>

Salin selepas log masuk

Output :

Kata kunci: lakukan

Kod:

<?php
// example to demonstrate do keyword
$x = 2;
do {
if($x > 2)
{
echo 'x is greater than 2';
}
else{
echo 'x is less than 2';
}
} while ($x < 2);
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Kata kunci: die();

Kod :

<?php
//example to demonstrate die keyword
$conn = mysqli_connect('localhost','root','','dbname');
if(!$conn) {
die("Unable to connect ");
}
?>

Salin selepas log masuk

Output:

Kata kunci: gema

Kod:

<?php
// example to demonstrate echo keyword
echo 'Hello! ';
$name = 'John Doe';
echo 'My name is '. $name;
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Kata kunci: lain

Kod:

<?php
// example to demonstrate else keyword
$a = 10;
if ($a > 5) {
echo "a is greater than 10";
} else {
echo "a is not greater than 10";
}
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Kata kunci: elseif

Kod:

<?php
// example to demonstrate elseif keyword
$a = 10;
if ($a > 10) {
echo "a is greater than 10";
} elseif ($a == 10) {
echo "a is equal to 10";
} else {
echo "a is smaller than 10";
}
?>

Salin selepas log masuk

Output :

Kata kunci: kosong

Kod:

<?php
// example to demonstrate empty keyword
$str = 'Hello World!';
if(empty($str)) {
echo 'Variable is empty';
} else {
echo $str;
}
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Kata kunci: endfor

Kod:

<?php
// example to demonstrate endfor keyword
for($i=0;$i<5;$i++) :
echo "<br/>".$i;
endfor;
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Kata kunci: endif

Kod :

<?php
// example to demonstrate endif keyword
if ($a > 10):
echo "a is greater than 10";
elseif ($a >10) :
echo "a is equal to 10";
else:
echo "a is not equal to 10";
endif;
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Kata kunci: endforeach

Kod:

<?php
// example to demonstrate endforeach keyword
$arr = array(1,2,3,4,5,6,7,8,9,10);
foreach ($arr as $key=>$value):
echo '<br>'.$value;
endforeach;
?>

Salin selepas log masuk

Output:

Kata kunci: suis hujung

Kod:

<?php
// example to demonstrate endswitch keyword
$fruits = 'Cherries';
switch ($fruits):
case 'Apple':
echo "Apple";
break;
case 'Banana':
echo "Banana";
break;
case 'Papaya':
echo "Papaya";
break;
default:
echo "Fruit is not Apple, Banana or Papaya ";
break;
endswitch;
?>

Salin selepas log masuk

Output:

Kata kunci: endwhile

Kod:

<?php
// example to demonstrate endwhile keyword
$i = 0;
while($i<5):
echo "<br>".$i;
$i++;
endwhile;
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: eval()

Code:

<?php
//example to demonstrate eval keyword
$string1 = 'World';
$string2 = 'John Doe';
$string = 'Hello $string1 .  My name is $string2';
echo "<br>".$string;
eval("\$string = \"$string\";");
echo "<br>".$string;
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: exit()

This keyword when encountered in a script, terminates the execution of the script.

Keyword: extends()

Code:

<?php
//example to demonstrate extends keyword
class ParentClass {
var $string = 'PHP';
public function display() {
echo $this->string;
}
}
class ExtendClass extends ParentClass {
public function display() {
echo 'Hello World!';
}
}
$obj1 = new ExtendClass;
$obj1->display();
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: final

Code:

<?php
//example to demonstrate final keyword
class ParentClass {
var $string = 'PHP';
final public function display() {
echo $this->string;
}
}
class ExtendClass extends ParentClass {
public function display() {
echo 'Hello World!';
}
}
$obj1 = new ExtendClass;
$obj1->display();
?>

Salin selepas log masuk

Output :

Kata Kunci PHP

Keyword: catch

Code:

<?php
//example to demonstrate catch keyword
try {
$num1 = 10;
$num2 = 0;
if($num1 / $num2) {
throw new Exception('Divide By Zero');
}
} catch (Exception $e) {
echo '<br>'.$e->getMessage();
}
?>

Salin selepas log masuk

Output:

Keyword: for

Code:

<?php
// example to demonstrate for keyword
for($i=0; $i<10; $i++) {
if($i == 5) {
break;
}
echo '<br>'.$i;
}
?>

Salin selepas log masuk

Output :

Keyword: foreach

Code:

<?php
// example to demonstrate foreach keyword
$array = array(10,20,30,40,50);
foreach($array as $value) {
echo '<br>'.$value/10;
}
?>

Salin selepas log masuk

Output:

Keyword: function()

Code:

<?php
function calSum($a , $b) {
$c = $a + $b;
return $c;
}
$result = calSum(10 , 20);
echo '<br> The sum  :  '.$result;
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword 34: global

Code:

<?php
//example to demonstrate global keyword
$a = 10;
$b = 20;
function fun() {
global $a;
global $b;
$result = $a + $b;
return $result;
}
$f = fun();
echo 'The result is '.$f;
?>

Salin selepas log masuk

Output:

Keyword: if

Code:

<?php
// example to demonstrate if keyword
$sum = 10;
if($sum == 10) {
echo 'Sum is 10';
} else {
echo 'Sum is not 10';
}
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: implements

Code:

<?php
//example to demonstrate interface keyword
interface One
{
public function first();
}
class MainClass implements One {
public function first() {
echo 'This is the First function';
}
}
$obj = new MainClass;
echo $obj->first();
?>

Salin selepas log masuk

Output :

Kata Kunci PHP

Keyword: include

Code:

file.php

<?php
//example to demonstrate include keyword
$a = 'The Earth';
$b = 'Round';
?>

Salin selepas log masuk

index.php

<?php
include 'file.php';
echo $a . ' is '. $b. ' in Shape';
?>

Salin selepas log masuk

Keyword : include_once

Code:

file.php

<?php
//example to demonstrate include_once keyword
$a = 'The Earth';
$b = 'Round';
?>

Salin selepas log masuk

index.php

<?php
Include_once 'file.php';
echo $a . ' is '. $b. ' in Shape';
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: instanceOf

Code:

<?php
//example to demonstrate instanceOf keyword
class MainClass
{
public function MainCLassMethod(){
echo 'Hello World!';
}
}
class ExtendedClass extends MainClass
{
public function ExtendedClassMethod(){
echo 'Have a Nice Day!';
}
}
$obj1 = new ExtendedClass;
var_dump($obj1 instanceOf ExtendedClass);
?>

Salin selepas log masuk

Output:

Keyword: Interface

Code:

<?php
//example to demonstrate interface keyword
interface One
{
public function one();
}
interface Two
{
public function two();
}
class MainClass implements One, Two {
public function one() {
echo '<br> This is the one function';
}
public function two() {
echo '<br> This is the two function';
}
}
$obj = new MainClass;
echo $obj->one();
echo $obj->two();
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: isset

Code:

<?php
//example to demonstrate isset keyword
$stringOne = '';
var_dump(isset($stringOne));
$stringTwo = NULL;
var_dump(isset($stringTwo));
?>

Salin selepas log masuk

Output :

Kata Kunci PHP

Keyword: list

Code:

<?php
//example to demonstrate list keyword
$names = array('Ram','Mohan','Raghav');
list($person1, $person2, $person3) = $names;
echo "$person1, $person2 and $person3 are friends";
?>

Salin selepas log masuk

Output:

Keyword: new

Code:

<?php
//example to demonstrate new keyword
class Student
{
public function score($name, $subject, $marks) {
echo "$name scored $marks marks in $subject";
}
}
$obj = new Student;
$obj->score('Sunil','Maths',90);
?>

Salin selepas log masuk

Output:

Keyword: or

Code:

<?php
//example to demonstrate or keyword
$a = 10;
$b = 11;
if($a ==10  or $b == 12) {
echo 'Result :  True';
}
else
{
echo 'Result : False';
}
?>

Salin selepas log masuk

Output :

Kata Kunci PHP

Keyword: print

Code:

<?php
//example to demonstrate print keyword
$str = "PHP Programming";
print($str);
$stringOne = "Shyam, ";
$stringTwo = "How are you?";
print "<br>"."Hello $stringOne $stringTwo";
?>

Salin selepas log masuk

Output :

Kata Kunci PHP

Keyword: private

Code:

<?php
//example to demonstrate private keyword
class MainClass
{
private $str = 'Private';
function PrivateMethod()
{
echo 'In '. $this->str. ' Method';
}
}
$obj = new MainClass();
$obj->PrivateMethod(); //Shows Private Method
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: public

Code:

<?php
//example to demonstrate public keyword
class MainClass
{
public $str = 'Public';
function PublicMethod()
{
echo 'In '. $this->str. ' Method';
}
}
$obj = new MainClass();
$obj->PublicMethod(); //Shows Public Method
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: protected

Code:

<?php
//example to demonstrate protected keyword
class MainClass
{
protected $str = 'Protected';
function ProtectedMethod()
{
echo 'In '. $this->str. ' Method';
}
}
$obj = new MainClass();
$obj->ProtectedMethod(); //Shows Protected Method
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: return

Code:

<?php
//example to demonstrate return keyword
function sum() {
$a = 10;
$b = 20;
$c = $a +$b;
return $c;
}
$result = sum();
echo 'Sum : ' . $result;
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: switch

Code:

<?php
//example to demonstrate switch keyword
$i= 3;
switch($i) {
case 1:
echo "<br>"."One";
break;
case 2:
echo "<br>"."Two";
break;
case 3:
echo "<br>"."Three";
break;
default:
echo "<br>"."Default";
}
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: throw

Code:

<?php
//example to demonstrate throw keyword
function division($x, $y) {
try {
if($y == 0) {
throw new Exception('Divide By Zero');
}
}
catch (Exception $e) {
echo '<br>'.$e->getMessage();
}
}
division(10,0);
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: Try

Code:

<?php
//example to demonstrate try keyword
try{
$arr = array();
$arr_length = count($arr);
if($arr_length == 0) {
throw new Exception('Error : Empty Array!');
}
else {
echo 'Array found';
print_r($arr);
}
}
catch(Exception $e) {
echo '<br>'.$e->getMessage();
}
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Keyword: unset

Code:

<?php
//example to demonstrate unset keyword
echo 'Hello World!'.'<br>';
$a = 10;
echo $a;
unset($a);
// echo $a; //this line when uncommented shows error : Undefined variable,  as the variable is unset
?>

Salin selepas log masuk

Output:

Keyword: var

Code:

<?php
//example to demonstrate var keyword
class MainClass
{
var $str = 'PHP Programming';
public function displayMsg() {
echo $this->str;
}
}
$obj = new MainClass;
$obj->displayMsg();
?>

Salin selepas log masuk

Output:

Keyword: while

Code:

<?php
//example to demonstrate while keyword
$i = 0;
while ($i<10) {
echo '<br>'. $i;
$i++;
}
?>

Salin selepas log masuk

Output:

Kata Kunci PHP

Conclusion

In this article, you will learn about keywords in PHP with examples. These examples explain the usage of each of the keyword in PHP.

Atas ialah kandungan terperinci Kata Kunci PHP. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!